 
<html> 
<head> 
<meta http-equiv="Content-Type" content="text/html; charset=gb2312"> 
<title>图片的左右移动，动画效果的实现</title> 
<script LANGUAGE="JavaScript"><!-- 
step = 0; 
obj = new Image(); 
function anim(xp,xk,smer) 
{ 
obj.style.left = x; 
x += step*smer; 
if (x>=(xk+xp)/2) { 
if (smer == 1) step--; 
else step++; 
} 
else { 
if (smer == 1) step++; 
else step--; 
} 
if (x >= xk) { 
x = xk; 
smer = -1; 
} 
if (x <= xp) { 
x = xp; 
smer = 1; 
} 
setTimeout('anim('+xp+','+xk+','+smer+')', 50); 
} 
function moveLR(objID,movingarea_width,c) 
{ 
if (navigator.appName=="Netscape") window_width = window.innerWidth; 
else window_width = document.body.offsetWidth; 
obj = document.images[objID]; 
image_width = obj.width; 
x1 = obj.style.left; 
x = Number(x1.substring(0,x1.length-2)); 
if (c == 0) { 
if (movingarea_width == 0) { 
right_margin = window_width - image_width; 
anim(x,right_margin,1); 
} 
else { 
right_margin = x + movingarea_width - image_width; 
if (movingarea_width < x + image_width) window.alert("No space for moving!"); 
else anim(x,right_margin,1); 
} 
} 
else { 
if (movingarea_width == 0) right_margin = window_width - image_width; 
else { 
x = Math.round((window_width-movingarea_width)/2); 
right_margin = Math.round((window_width+movingarea_width)/2)-image_width; 
} 
anim(x,right_margin,1); 
} 
} 
//--></script> 
</head> 

<body> 
<a href="/" target="_blank"> 
<img src="/images/logo.gif" name="picture" 
style="position: absolute; top: 70px; left: 30px;" BORDER="0"> 
</a> 
<script LANGUAGE="JavaScript"><!-- 
setTimeout("moveLR('picture',300,1)",10); 
//--></script> 
</body> 
</html> 
